T5 4Motion is really about added traction than serious 4wdriving - that said with certain modifications it could go anywhere.

The Touareg with 4Motion and Audi Q7 with quattro are capable vehicles and with the right tyres they could possible go further than some could imagine - Audi did a Trans-Continental stint when they launched the Q7 proving that it is capable without low range.

Touareg with 4XMotion will go anywhere but has very limited backup in aftermarket modifications like bullbars etc.

Amarok would be the right vehicle if you plan to go bush IMO as there is heaps of aftermarket accessories available here with ARB etc.